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# Copyright (C) 2006, 2007, 2009 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Blackbox tests for debugger breakin"""
try:
import ctypes
have_ctypes = True
except ImportError:
have_ctypes = False
import errno
import os
import signal
import subprocess
import sys
import time
from bzrlib import (
breakin,
errors,
tests,
)
class TestBreakin(tests.TestCase):
# FIXME: If something is broken, these tests may just hang indefinitely in
# wait() waiting for the child to exit when it's not going to.
def setUp(self):
super(TestBreakin, self).setUp()
if breakin.determine_signal() is None:
raise tests.TestSkipped('this platform is missing SIGQUIT'
' or SIGBREAK')
if sys.platform == 'win32':
# Windows doesn't have os.kill, and we catch the SIGBREAK signal.
# We trigger SIGBREAK via a Console api so we need ctypes to access
# the function
if not have_ctypes:
raise tests.UnavailableFeature('ctypes')
self._send_signal = self._send_signal_win32
else:
self._send_signal = self._send_signal_via_kill
def _send_signal_via_kill(self, pid, sig_type):
if sig_type == 'break':
sig_num = signal.SIGQUIT
elif sig_type == 'kill':
sig_num = signal.SIGKILL
else:
raise ValueError("unknown signal type: %s" % (sig_type,))
os.kill(pid, sig_num)
def _send_signal_win32(self, pid, sig_type):
"""Send a 'signal' on Windows.
Windows doesn't really have signals in the same way. All it really
supports is:
1) Sending SIGINT to the *current* process group (so self, and all
children of self)
2) Sending SIGBREAK to a process that shares the current console,
which can be in its own process group.
So we have start_bzr_subprocess create a new process group for the
spawned process (via a flag to Popen), and then we map
SIGQUIT to GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT)
SIGKILL to TerminateProcess
"""
if sig_type == 'break':
CTRL_BREAK_EVENT = 1
# CTRL_C_EVENT = 0
ret = ctypes.windll.kernel32.GenerateConsoleCtrlEvent(
CTRL_BREAK_EVENT, pid)
if ret == 0: #error
err = ctypes.FormatError()
raise RuntimeError('failed to send CTRL_BREAK: %s'
% (err,))
elif sig_type == 'kill':
# Does the exit code matter? For now we are just setting it to
# something other than 0
exit_code = breakin.determine_signal()
ctypes.windll.kernel32.TerminateProcess(pid, exit_code)
def _popen(self, *args, **kwargs):
if sys.platform == 'win32':
CREATE_NEW_PROCESS_GROUP = 512
# This allows us to send a signal to the child, *without* also
# sending it to ourselves
kwargs['creationflags'] = CREATE_NEW_PROCESS_GROUP
return super(TestBreakin, self)._popen(*args, **kwargs)
def _dont_SIGQUIT_on_darwin(self):
if sys.platform == 'darwin':
# At least on Leopard and with python 2.6, this test will raise a
# popup window asking if the python failure should be reported to
# Apple... That's not the point of the test :) Marking the test as
# not applicable Until we find a way to disable that intrusive
# behavior... --vila20080611
raise tests.TestNotApplicable(
'%s raises a popup on OSX' % self.id())
def _wait_for_process(self, pid, sig=None):
# We don't know quite how long waiting for the process 'pid' will take,
# but if it's more than 10s then it's probably not going to work.
for i in range(100):
time.sleep(0.1)
if sig is not None:
self._send_signal(pid, sig)
# Use WNOHANG to ensure we don't get blocked, doing so, we may
# leave the process continue after *we* die...
# Win32 doesn't support WNOHANG, so we just pass 0
opts = getattr(os, 'WNOHANG', 0)
try:
# TODO: waitpid doesn't work well on windows, we might consider
# using WaitForSingleObject(proc._handle, TIMEOUT)
# instead. Most notably, the WNOHANG isn't allowed, so
# this can hang indefinitely.
pid_killed, returncode = os.waitpid(pid, opts)
if (pid_killed, returncode) != (0, 0):
if sig is not None:
# high bit in low byte says if core was dumped; we
# don't care
status, sig = (returncode >> 8, returncode & 0x7f)
return True, sig
except OSError, e:
if e.errno in (errno.ECHILD, errno.ESRCH):
# The process doesn't exist anymore
return True, None
else:
raise
return False, None
# port 0 means to allocate any port
_test_process_args = ['serve', '--port', 'localhost:0']
def test_breakin(self):
# Break in to a debugger while bzr is running
# we need to test against a command that will wait for
# a while -- bzr serve should do
proc = self.start_bzr_subprocess(self._test_process_args,
env_changes=dict(BZR_SIGQUIT_PDB=None))
# wait for it to get started, and print the 'listening' line
proc.stderr.readline()
# first sigquit pops into debugger
self._send_signal(proc.pid, 'break')
# Wait for the debugger to acknowledge the signal reception
# Note that it is possible for this to deadlock if the child doesn't
# acknowlege the signal and write to stderr. Perhaps we should try
# os.read(proc.stderr.fileno())?
err = proc.stderr.readline()
self.assertContainsRe(err, r'entering debugger')
# Now that the debugger is entered, we can ask him to quit
proc.stdin.write("q\n")
# We wait a bit to let the child process handles our query and avoid
# triggering deadlocks leading to hangs on multi-core hosts...
dead, sig = self._wait_for_process(proc.pid)
if not dead:
# The process didn't finish, let's kill it before reporting failure
dead, sig = self._wait_for_process(proc.pid, 'kill')
if dead:
raise tests.KnownFailure(
"subprocess wasn't terminated, it had to be killed")
else:
self.fail("subprocess %d wasn't terminated by repeated SIGKILL",
proc.pid)
def test_breakin_harder(self):
"""SIGQUITting twice ends the process."""
self._dont_SIGQUIT_on_darwin()
proc = self.start_bzr_subprocess(self._test_process_args,
env_changes=dict(BZR_SIGQUIT_PDB=None))
# wait for it to get started, and print the 'listening' line
proc.stderr.readline()
# break into the debugger
self._send_signal(proc.pid, 'break')
# Wait for the debugger to acknowledge the signal reception (since we
# want to send a second signal, we ensure it doesn't get lost by
# validating the first get received and produce its effect).
err = proc.stderr.readline()
self.assertContainsRe(err, r'entering debugger')
dead, sig = self._wait_for_process(proc.pid, 'break')
self.assertTrue(dead)
# Either the child was dead before we could read its status, or the
# child was dead from the signal we sent it.
self.assertTrue(sig in (None, breakin.determine_signal()))
def test_breakin_disabled(self):
self._dont_SIGQUIT_on_darwin()
proc = self.start_bzr_subprocess(self._test_process_args,
env_changes=dict(BZR_SIGQUIT_PDB='0'))
# wait for it to get started, and print the 'listening' line
proc.stderr.readline()
# first hit should just kill it
self._send_signal(proc.pid, 'break')
proc.wait()
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